python · hugovk · Mar 29, 2025 · Mar 27, 2025 · Mar 27, 2025 · Mar 27, 2025
diff --git a/Lib/test/libregrtest/main.py b/Lib/test/libregrtest/main.py
@@ -630,9 +630,9 @@ def _add_ci_python_opts(self, python_opts, keep_environ):
         if not sys.stdout.write_through:
             python_opts.append('-u')
 
-        # Add warnings filter 'default'
+        # Add warnings filter 'error'
         if 'default' not in sys.warnoptions:
-            python_opts.extend(('-W', 'default'))
+            python_opts.extend(('-W', 'error'))
 
         # Error on bytes/str comparison
         if sys.flags.bytes_warning < 2:

diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
@@ -6,6 +6,7 @@
 import contextlib
 import dataclasses
 import functools
+import logging
 import _opcode
 import os
 import re
@@ -386,7 +387,7 @@ def skip_if_buildbot(reason=None):
     try:
         isbuildbot = getpass.getuser().lower() == 'buildbot'
     except (KeyError, OSError) as err:
-        warnings.warn(f'getpass.getuser() failed {err}.', RuntimeWarning)
+        logging.getLogger(__name__).warning('getpass.getuser() failed %s.', err, exc_info=err)
         isbuildbot = False
     return unittest.skipIf(isbuildbot, reason)
 
@@ -1079,8 +1080,7 @@ def start(self):
         try:
             f = open(self.procfile, 'r')
         except OSError as e:
-            warnings.warn('/proc not available for stats: {}'.format(e),
-                          RuntimeWarning)
+            logging.getLogger(__name__).warning('/proc not available for stats: %s', e, exc_info=e)
             sys.stderr.flush()
             return
 

diff --git a/Lib/test/support/numbers.py b/Lib/test/support/numbers.py
@@ -0,0 +1,80 @@
+# These are shared with test_tokenize and other test modules.
+#
+# Note: since several test cases filter out floats by looking for "e" and ".",
+# don't add hexadecimal literals that contain "e" or "E".
+VALID_UNDERSCORE_LITERALS = [
+    '0_0_0',
+    '4_2',
+    '1_0000_0000',
+    '0b1001_0100',
+    '0xffff_ffff',
+    '0o5_7_7',
+    '1_00_00.5',
+    '1_00_00.5e5',
+    '1_00_00e5_1',
+    '1e1_0',
+    '.1_4',
+    '.1_4e1',
+    '0b_0',
+    '0x_f',
+    '0o_5',
+    '1_00_00j',
+    '1_00_00.5j',
+    '1_00_00e5_1j',
+    '.1_4j',
+    '(1_2.5+3_3j)',
+    '(.5_6j)',
+]
+INVALID_UNDERSCORE_LITERALS = [
+    # Trailing underscores:
+    '0_',
+    '42_',
+    '1.4j_',
+    '0x_',
+    '0b1_',
+    '0xf_',
+    '0o5_',
+    '0 if 1_Else 1',
+    # Underscores in the base selector:
+    '0_b0',
+    '0_xf',
+    '0_o5',
+    # Old-style octal, still disallowed:
+    '0_7',
+    '09_99',
+    # Multiple consecutive underscores:
+    '4_______2',
+    '0.1__4',
+    '0.1__4j',
+    '0b1001__0100',
+    '0xffff__ffff',
+    '0x___',
+    '0o5__77',
+    '1e1__0',
+    '1e1__0j',
+    # Underscore right before a dot:
+    '1_.4',
+    '1_.4j',
+    # Underscore right after a dot:
+    '1._4',
+    '1._4j',
+    '._5',
+    '._5j',
+    # Underscore right after a sign:
+    '1.0e+_1',
+    '1.0e+_1j',
+    # Underscore right before j:
+    '1.4_j',
+    '1.4e5_j',
+    # Underscore right before e:
+    '1_e1',
+    '1.4_e1',
+    '1.4_e1j',
+    # Underscore right after e:
+    '1e_1',
+    '1.4e_1',
+    '1.4e_1j',
+    # Complex cases with parens:
+    '(1+1.5_j_)',
+    '(1+1.5_j)',
+]
diff --git a/Lib/test/support/os_helper.py b/Lib/test/support/os_helper.py
@@ -1,6 +1,7 @@
 import collections.abc
 import contextlib
 import errno
+import logging
 import os
 import re
 import stat
@@ -378,8 +379,12 @@ def _waitfor(func, pathname, waitall=False):
             # Increase the timeout and try again
             time.sleep(timeout)
             timeout *= 2
-        warnings.warn('tests may fail, delete still pending for ' + pathname,
-                      RuntimeWarning, stacklevel=4)
+        logging.getLogger(__name__).warning(
+            'tests may fail, delete still pending for %s',
+            pathname,
+            stack_info=True,
+            stacklevel=4,
+        )
 
     def _unlink(filename):
         _waitfor(os.unlink, filename)
@@ -494,9 +499,14 @@ def temp_dir(path=None, quiet=False):
         except OSError as exc:
             if not quiet:
                 raise
-            warnings.warn(f'tests may fail, unable to create '
-                          f'temporary directory {path!r}: {exc}',
-                          RuntimeWarning, stacklevel=3)
+            logging.getLogger(__name__).warning(
+                "tests may fail, unable to create temporary directory %r: %s",
+                path,
+                exc,
+                exc_info=exc,
+                stack_info=True,
+                stacklevel=3,
+            )
     if dir_created:
         pid = os.getpid()
     try:
@@ -527,9 +537,15 @@ def change_cwd(path, quiet=False):
     except OSError as exc:
         if not quiet:
             raise
-        warnings.warn(f'tests may fail, unable to change the current working '
-                      f'directory to {path!r}: {exc}',
-                      RuntimeWarning, stacklevel=3)
+        logging.getLogger(__name__).warning(
+            'tests may fail, unable to change the current working directory '
+            'to %r: %s',
+            path,
+            exc,
+            exc_info=exc,
+            stack_info=True,
+            stacklevel=3,
+        )
     try:
         yield os.getcwd()
     finally:

diff --git a/Lib/test/test_complex.py b/Lib/test/test_complex.py
@@ -2,8 +2,10 @@
 import sys
 from test import support
 from test.support.testcase import ComplexesAreIdenticalMixin
-from test.test_grammar import (VALID_UNDERSCORE_LITERALS,
-                               INVALID_UNDERSCORE_LITERALS)
+from test.support.numbers import (
+    VALID_UNDERSCORE_LITERALS,
+    INVALID_UNDERSCORE_LITERALS,
+)
 
 from random import random
 from math import isnan, copysign

@@ -24,6 +24,7 @@
 with the corresponding argument.
 """
 
+import logging
 import math
 import os, sys
 import operator
@@ -5932,8 +5933,9 @@ def tearDownModule():
     if C: C.setcontext(ORIGINAL_CONTEXT[C].copy())
     P.setcontext(ORIGINAL_CONTEXT[P].copy())
     if not C:
-        warnings.warn('C tests skipped: no module named _decimal.',
-                      UserWarning)
+        logging.getLogger(__name__).warning(
+            'C tests skipped: no module named _decimal.'
+        )
     if not orig_sys_decimal is sys.modules['decimal']:
         raise TestFailed("Internal error: unbalanced number of changes to "
                          "sys.modules['decimal'].")

diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
@@ -9,8 +9,10 @@
 
 from test import support
 from test.support.testcase import FloatsAreIdenticalMixin
-from test.test_grammar import (VALID_UNDERSCORE_LITERALS,
-                               INVALID_UNDERSCORE_LITERALS)
+from test.support.numbers import (
+    VALID_UNDERSCORE_LITERALS,
+    INVALID_UNDERSCORE_LITERALS,
+)
 from math import isinf, isnan, copysign, ldexp
 import math
 

diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
@@ -16,88 +16,10 @@
 import typing
 from test.typinganndata import ann_module2
 import test
-
-# These are shared with test_tokenize and other test modules.
-#
-# Note: since several test cases filter out floats by looking for "e" and ".",
-# don't add hexadecimal literals that contain "e" or "E".
-VALID_UNDERSCORE_LITERALS = [
-    '0_0_0',
-    '4_2',
-    '1_0000_0000',
-    '0b1001_0100',
-    '0xffff_ffff',
-    '0o5_7_7',
-    '1_00_00.5',
-    '1_00_00.5e5',
-    '1_00_00e5_1',
-    '1e1_0',
-    '.1_4',
-    '.1_4e1',
-    '0b_0',
-    '0x_f',
-    '0o_5',
-    '1_00_00j',
-    '1_00_00.5j',
-    '1_00_00e5_1j',
-    '.1_4j',
-    '(1_2.5+3_3j)',
-    '(.5_6j)',
-]
-INVALID_UNDERSCORE_LITERALS = [
-    # Trailing underscores:
-    '0_',
-    '42_',
-    '1.4j_',
-    '0x_',
-    '0b1_',
-    '0xf_',
-    '0o5_',
-    '0 if 1_Else 1',
-    # Underscores in the base selector:
-    '0_b0',
-    '0_xf',
-    '0_o5',
-    # Old-style octal, still disallowed:
-    '0_7',
-    '09_99',
-    # Multiple consecutive underscores:
-    '4_______2',
-    '0.1__4',
-    '0.1__4j',
-    '0b1001__0100',
-    '0xffff__ffff',
-    '0x___',
-    '0o5__77',
-    '1e1__0',
-    '1e1__0j',
-    # Underscore right before a dot:
-    '1_.4',
-    '1_.4j',
-    # Underscore right after a dot:
-    '1._4',
-    '1._4j',
-    '._5',
-    '._5j',
-    # Underscore right after a sign:
-    '1.0e+_1',
-    '1.0e+_1j',
-    # Underscore right before j:
-    '1.4_j',
-    '1.4e5_j',
-    # Underscore right before e:
-    '1_e1',
-    '1.4_e1',
-    '1.4_e1j',
-    # Underscore right after e:
-    '1e_1',
-    '1.4e_1',
-    '1.4e_1j',
-    # Complex cases with parens:
-    '(1+1.5_j_)',
-    '(1+1.5_j)',
-]
-
+from test.support.numbers import (
+    VALID_UNDERSCORE_LITERALS,
+    INVALID_UNDERSCORE_LITERALS,
+)
 
 class TokenTests(unittest.TestCase):
 

@@ -10,6 +10,7 @@
 import importlib
 import io
 import itertools
+import logging
 import os
 import sys
 import sysconfig
@@ -113,7 +114,11 @@ def _conditional_import_module(self, module_name):
             return importlib.import_module(module_name)
         except ModuleNotFoundError as error:
             if self._warn_on_extension_import and module_name in builtin_hashes:
-                warnings.warn(f'Did a C extension fail to compile? {error}')
+                logging.getLogger(__name__).warning(
+                    'Did a C extension fail to compile? %s',
+                    error,
+                    exc_info=error,
+                )
         return None
 
     def __init__(self, *args, **kwargs):

diff --git a/Lib/test/test_int.py b/Lib/test/test_int.py
@@ -4,8 +4,10 @@
 import unittest
 from unittest import mock
 from test import support
-from test.test_grammar import (VALID_UNDERSCORE_LITERALS,
-                               INVALID_UNDERSCORE_LITERALS)
+from test.support.numbers import (
+    VALID_UNDERSCORE_LITERALS,
+    INVALID_UNDERSCORE_LITERALS,
+)
 
 try:
     import _pylong

@@ -2,6 +2,7 @@
 import contextlib
 import json
 import io
+import logging
 import os
 import os.path
 import pickle
@@ -69,8 +70,8 @@ def pack_exception(exc=None):
 def unpack_exception(packed):
     try:
         data = json.loads(packed)
-    except json.decoder.JSONDecodeError:
-        warnings.warn('incomplete exception data', RuntimeWarning)
+    except json.decoder.JSONDecodeError as e:
+        logging.getLogger(__name__).warning('incomplete exception data', exc_info=e)
         print(packed if isinstance(packed, str) else packed.decode('utf-8'))
         return None
     exc = types.SimpleNamespace(**data)

diff --git a/Lib/test/test_pty.py b/Lib/test/test_pty.py
@@ -135,8 +135,10 @@ def test_openpty(self):
                 new_dim = tty.tcgetwinsize(pty.STDIN_FILENO)
                 self.assertEqual(new_dim, target_dim,
                                  "pty.STDIN_FILENO window size unchanged")
-            except OSError:
-                warnings.warn("Failed to set pty.STDIN_FILENO window size.")
+            except OSError as e:
+                logging.getLogger(__name__).warning(
+                    "Failed to set pty.STDIN_FILENO window size.", exc_info=e,
+                )
                 pass
 
         try: